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glaze test for emmanuel cooper blue speckled mat, cone 5-6

updated fri 4 feb 05


Alisa Clausen on thu 3 feb 05

Glaze test for Emmanuel Cooper Blue Speckled mat, cone 5-6.

Glaze tested on white midrange stoneware fired in electric oxidation to =
1240c. (2264f)

Source: Clay Times, Nov/Dec. 2004
Credited to:

Firing ramp:
100c p/h to 600c (212f - 1112f)
150c p/h to 1140c (302f - 2084f)=20
80c p/h to 1240c (176f - 2264f)
5 min. soak
cool down max. to 800c (1472f)
Hold 1 hour
Shut off kiln

55 Potash
10 Lithium Carb.
10 Whiting
5 Ball Clay
20 Silica

0,25 Cobalt Carb.

Note: All raw materials are measured up or down to the nearest whole =
decimal. =20
Colorants or additives to a 100 gram test batch are measured in percent =
to the 100 gram test batch.

Gloss, medium blue glaze. Transparent and iron specks from clay body =
come through.

1 Copper Carb.=20
1 Cobalt Carb.
Semi mat, smooth glaze, very dark blue with slight crystal formation on =
surface. Very covering and opaque.

2 Copper Carb.
Gloss, pale green glaze. Crazed over all.

10 RIO
Gloss, dark glaze, breaking very dark grown to black.

Regards from Alisa in Denmark